Integration of green hydrogen in the Chilean industry: the case study of copper mining CAEX hauling trucks

Green hydrogen is becoming a key pillar in today’s energy transition towards decarbonization due to its advantageous qualities as a carbon-free energy carrier. Fast-growing economies with vast amounts of renewable energy sources like Chile are positioning to be majors green hydrogen producers in the near term due to the cheap electricity that can be achieved from solar PV or onshore wind energy. In this work, an overview of the main Chilean industries and most promising technological opportunities for integrating green hydrogen was done and it was found that the copper mining industry has the potential of decarbonizing the transportation of extracted materials in open pit mines with the replacement of diesel with green hydrogen in CAEX hauling trucks through the retrofit with dual hydrogen (60%) - diesel (40%) internal combustion engines (H2ICE) or reconversion into fuel cell electric vehicles (FCEV). Three major mining zones where identified and the potential hydrogen demand for the major copper mines in this zones was estimated for future scenarios considering the mines lifetime, energy projections and hydrogen market penetration of 10% by 2030 and 37% by 2050. On average, each H2ICE and FCEV trucks would need 600 and 1,000 kg of hydrogen respectively. A sub-area from Zone 1 in the north of Chile was selected as case of study and the levelized cost of hydrogen (LCOH) was calculated for different configurations considering off-grid plants and on-grid plants with PPA. The lowest LCOH achieved was of 3.11 $/kg with an oversized off-grid solar plant by 2030 and the lowest LCOH for 2050 was 1.44 $/kg obtained with CSP + TES. In order to ensure competitivity with diesel, green hydrogen should be lower than 2.80 $/kg, so economies of scale have to be achieved and electrolyzers capital investments cost have to be reduced at least down to the range of 600 – 700 $/kW in 2030 for being able to produce cheap and competitive solar green hydrogen in Chile. An estimation was done of the potential size and design of a green hydrogen supply chain from on-site solar hydrogen production to the hydrogen refueling stations (HRS) in each copper mine of the case of study. The most significant annual hydrogen demand was of 4,103 ton in Centinela mine for 17 H2ICE trucks or 10 FCEV trucks that would require a HRS with daily capacity of 11,241 kilograms and a H2 plant of 82 MW coupled with a solar PV plant of 114 MW. Finally, an analysis about the truck’s on-board storage challenge was performed considering crucial parameters like refueling filling rates, tanks weight, space availability and diesel truck’s performance. Globally, with today’s existing HRS technologies and standards, there is no an optimum storage configuration that could match the same operational performance than diesel CAEX trucks unless a much more competitive price of green hydrogen could compensate the potential economic losses due to higher filling times, frequency or extra weight. A reasonable range of on-board capacity storage system could be of 75 – 300 kilogram with type IV tanks at 350 or 700 bar for H2ICE and FCEV retrofitted CAEX trucks.